激光周边虹膜切开术在急性闭角型青光眼的临床应用

目的观察激光周边虹膜切开术在治疗急性闭角型青光眼临床前期及间歇期的效果,探讨其作用机制。方法 49例78只眼闭角型青光眼行激光周边虹膜切开术,采用倍频532 nm激光烧灼、ND：YAG激光击穿周边虹膜,术后观察前房反应、眼压,随访3-12个月。结果所有眼术后均出现了虹膜炎性反应,1 d后消退;一过性眼压升高3眼（22-30 mmHg）,经处理后降至正常;前房出血2眼,1 d后吸收;角膜内皮损伤混浊2眼,3 d后消退。结论激光周边虹膜切开术并发症少,不影响降压效果,适合于急性闭角型青光眼临床前期及间歇期的治疗。     

Active Iris Mechanics and Pupillary Block: Steady-State Analysis and Comparison with Anatomical Risk Factors

Primary angle-closure glaucoma arises when the iris physically obstructs outflow of aqueous humor, increasing the intraocular pressure and damaging the optic nerve. Pupillary block, the predominant mechanism for angle closure, is believed to be driven by mechanical interaction between the aqueous humor and the iris. We performed steady-state simulations of this coupled fluid-solid system, including an active sphincter to control pupil constriction. Model results compared favorably against Mapstone's pupil-blocking force analysis. We also evaluated anatomical risk factors and quantified their contributions to pupillary block and angle closure. The results showed that greater lens curvature and shorter iris-zonule distance contribute significantly to pupillary block and the associated narrowing of the angle. Surprisingly, the model predicted that maximum pupillary block and angle closure occur at the minimum pupil dilation, contradicting the clinical observation that angle closure is most severe in dark conditions. This discrepancy suggests the involvement of one or more phenomena not captured by our current model.     

Aqueous humor dynamics and the iris

Solutes concentration in the aqueous humor of the eye is highest near the ciliary processes in the posterior chamber (p.c.) and lowest near the trabecular meshwork in the anterior chamber (a.c.). The high osmotic gradient across the semipermeable iris causes it to easily move forward at this location and occasionally occlude the iridocorneal angle. Vector analysis of the forces generated by miosis helps explain on osmotic grounds why it reduces the intraocular pressure, while at the same time the analysis elucidates the reason for the higher frequency of angle closure glaucoma when the anterior chamber is shallow.     

Combined technique of argon-laser and neodymium-YAG laser photocoagulation for narrow-or closed-angle glaucoma

A combined laser technique was applied in 76 eyes with narrow- or closed-angle glaucoma. In the first act circular Argon-laser iridoplasty was performed, to be followed by peripheral Nd-YAG laser iridotomy. Before the laser application, intraocular pressure was decreased using medicamentous antiglaucoma therapy to 30 mmHg or less. Argon-laser iridoplasty was performed in the peripheral third of the total iris circumference applying cca 20 laser spots. Eight days later, Nd-YAG laser iridotomy was performed at the site of the previous Argon-laser spot. Postoperative intraocular pressure was normal in 64 out of 76 eyes (84.2%) on the last check-up, and the additional antiglaucoma medications was significantly reduced. In a small number of cases i.e. 24 eyes (31.6%), the medical therapy was altogether cancelled. In 12 eyes (15.8%) the laser treatment has failed, and antiglaucoma surgery had to be performed subsequently. The observation period ranged from 4 to 25 months.     

Endoscopic laser photocoagulation for management of neovascular glaucoma

We used endoscopic laser photocoagulation to treat neovascular glaucoma in eight eyes of seven patients. New vessels of the iris and anterior chamber disappeared or stabilized after photocoagulation in seven eyes (88%), while the vision improved in four eyes (50%). The endoscopy was excellent for observing the peripheral retina and ciliary process tissue. We found the endoscopic laser was suitable for wider photocoagulation of ischemic retina against media opacity.     

Ultrasonographic findings of experimental glaucoma in rabbits

Ocular ultrasonography is a valid and non-invasive diagnostic method used to evaluate ocular and retrobulbar structures, especially when opacity of the anterior segments precludes ophthalmic examination of deeper structures of the eye or when exophthalmos is present. This study describes the B-mode ultrasonographic findings of the globe in 10 rabbits with experimental glaucoma. Ultrasonography of the eyes, using Titan TM machine and 7 MHz linear array transducer, was performed transpalpebrally. Ocular ultrasonographic findings revealed two cases of increased corneal thickness, seven cases of change in the anterior chamber depth, one case of increased echogenicity in the anterior chamber, three cases of retinal detachment, one case of increased iris and ciliary body thickness and six cases of change in axial globe length. Increased echogenicity of the capsule, cortex and nucleus was found in two cases. Six cases showed change in lens diameter. Increased echogenicity and altered lens diameter are typical of cataract. Two cases of point-like lesions, mass and/or linear echodensities in mild extent were observed within the vitreous representing haemorrhage, vitreous degeneration or detachment. The B-mode ultrasonographic imaging technique has become an essential diagnostic tool in most ocular disease. This method provides additional information allowing the clinician to offer more accurate diagnosis, treatment and prognosis in glaucoma.     

Altered aquaporin expression in glaucoma eyes

Aquaporins (AQP) are channels in the cell membrane that mainly facilitate a passive transport of water. In the eye, AQPs are expressed in the ciliary body and retina and may contribute to the pathogenesis of glaucoma and optic neuropathy. We investigated the expression of AQP1, AQP3, AQP4, AQP5, AQP7 and AQP9 in human glaucoma eyes compared with normal eyes. Nine glaucoma eyes were examined. Of these, three eyes were diagnosed with primary open angle glaucoma; three eyes had neovascular glaucoma; and three eyes had chronic angle‐closure glaucoma. Six eyes with normal intraocular pressure and without glaucoma were used as control. Immunohistochemistry was performed using antibodies against AQP1, AQP3, AQP4, AQP5, AQP7 and AQP9. For each specimen, optical densities of immunoprecipitates were measured using Photoshop and the staining intensities were calculated. Immunostaining showed labelling of AQP7 and AQP9 in the nonpigmented ciliary epithelium and the staining intensities were significantly decreased in glaucoma eyes (p = 0.003; p = 0.018). AQP7 expression in the Müller cell endfeet was increased (p = 0.046), and AQP9 labelling of the retinal ganglion cells (RGC) showed decreased intensity (p = 0.037). No difference in AQP1, AQP4 and AQP9 expression was found in the optic nerve fibres. This study is the first investigating AQPs in human glaucoma eyes. We found a reduced expression of AQP9 in the retinal ganglion cells of glaucoma eyes. Glaucoma also induced increased AQP7 expression in the Müller cell endfeet. In the ciliary body of glaucoma eyes, the expression of AQP7 and AQP9 was reduced. Therefore, the expression of AQPs seems to play a role in glaucoma.     

Laser therapy of glaucoma

The introduction of argon-laser iridotomy and argon-laser trabeculoplasty have had a beneficial impact on the treatment of glaucoma. Recent attention has been given to complications of anterior segment laser therapy. Of most concern is an acute rise in intraocular pressure which may be as great as 20 mmHg. Since patients undergoing anterior segment laser therapy usually have pre-existing visual compromise, this rise in intraocular pressure may be detrimental. This pressure rise rarely requires surgery. Until long-term follow-up is available, and complications are better understood, these new treatment modalities should be employed with caution.     

Aetiopathological aspects of inherited lens dislocation in the Tibetan Terrier

Four litters of Tibetan Terriers were bred in order to study the ocular pathology of primary lens luxation, which in this breed is due to an autosomal recessive gene. Scanning and transmission electron microscopy were carried out on ocular tissues of 5 dogs from 2 homozygous litters killed at various ages up to the time of onset of clinical subluxation. All eyes showed zonular abnormality, in particular a bizarre arrangement of fibrillar material associated with the ciliary processes and relating to the system of zonular fibres inserting posteriorly at the lens equator. A further litter, the result of an affected X carrier mating and killed at 20 months of age, included 2 affected and 2 unaffected dogs. The pathological changes noted in affected eyes are reconciled with the clinical signs observed in 4 homozygous dogs developing lens luxation.     

Spontaneous Anterior Lens Capsular Dehiscence Causing Lens Particle Glaucoma

To report acute onset lens particle glaucoma associated with a spontaneous anterior capsular dehiscence. A 66-year-old man presented with spontaneous anterior lens capsule dehiscence with an acute onset of right eye pain that was associated with white particles in the anterior chamber angle and intraocular pressure (IOP) of 55 mmHg. No trauma or other inflammatory antecedents were reported. A hypermature cataract was observed at slit lamp exam. After medical treatment without IOP control, we performed extracapsular cataract extraction and anterior vitrectomy. Anterior chamber aspirate confirmed the presence of macrophages. The postoperative IOP at one month was 16 mmHg OD without medication. Spontaneous dehiscence of the anterior lens capsule in a patient with a hypermature cataract may release lens cortical material, resulting in lens particle glaucoma. Prompt surgical removal of the lens material usually controls the high IOP, and the need for additional glaucoma surgery is not common.     

Scierai ectasia associated with hereditary retinal dysplasia in a mutant strain of Japanese quail (Coturnix coturnix japonica).

Ocular defects and age-related lesions in mutant (GUB strain) Japanese quail (Coturnix coturnix japonica), phenotypically characterised by silver plumage, are described. Grossly, a circular area of hypopigmentation in the posterior retina with thinning of the subjacent sciera was observed in all GUB quails. As the birds matured, the thinned sciera progressed to scierai ectasia. Histologically, the sciera at the ectatic area consisted of an outer fibrous layer and was devoid of the inner cartilaginous shell. Atypical differentiation and duplication of the retina with absence of the choroid was common at the ectatic area. The retina, choroid, ciliary body and iris were all poorly pigmented. With increasing age, the ectatic area became cystic, and the duplicated retina degenerated and atrophied. In addition, there were mononuclear cell infiltration in the stroma of the iris and ciliary body, anterior and posterior synechiae, cataract and/or glaucoma in aged GUB quails. These findings suggest that posterior scierai ectasia in the GUB strain of Japanese quails may have developed secondarily to a congenital structural defect of the posterior portion of sciera associating with general ocular defects.     

应用超声生物显微镜观察小梁切除术后的房角改变

目的 应用超声生物显微镜（UBM）观察原发性闭角型青光眼（PACG）小梁切除术后的房角改变。方法：PACG患者30人（30只眼），行巩膜板层下小梁切除术，分别于术前和术后使用UBM观察房角形态并测量。结果：术前2只眼存在睫状体脱离。ACD、AOD500,TIA、TCPD、ID1术前术后比较差异均无显著性（P〉0．05）。结论：UBM有利于发现青光眼手术前后的睫状体脱离。小梁切除术对PACG的房角结构无改善。     

Anophthalmia-plus syndrome: a clinical report and review of the literature

We describe a term male infant of healthy non-consanguineous parents, born with congenital malformations, including bilateral cleft palate and lip, mild microphthalmia with iris coloboma and glaucoma of the right eye, and blepharophimosis with severe microphthalmia of the left eye. Spine radiograph and MRI showed first sacral hemivertebra with spina bifida, and agenesis of the 2nd, 3rd, 4th, and 5th sacral vertebrae and coccyx. Spine MRI showed caudal tethering of spinal cord at L(3) level, filum terminalis lipoma and a syringomyelia. Brain ultrasound and MRI showed hypoplasia of corpus callosum with mild dilatation of the lateral ventricles. Orbital MRI showed bilateral microphthalmia-distorted small left eyeball with posteriorly located lens, and a split vitreous body in the right eye, suggestive of primary hyperplastic vitreous. The karyotype was normal. Summary of the findings in nine cases (our case and eight published cases) support the notion that anophthalmia-plus syndrome (APS) is a distinct syndrome. Gene locus of APS is yet to be identified.     

Embryology and morphology of microphthalmia in transgenic mice expressing a gamma F-crystallin/diphtheria toxin A hybrid gene.

BACKGROUND: Transgenic mice in which elongating lens fiber cells were ablated resulting in microphthalmia have been reported, however, their embryology and detailed morphology have not. EXPERIMENTAL DESIGN: The morphology of homozygous and hemizygous CDI, transgenic mice carrying the gamma FDT-A gene was studied by light microscopy on different days of gestation as well as postpartum. The findings were compared with normal CD-1 wild type controls. RESULTS: The earliest changes in mouse embryos transgenic for the gamma F-crystallin/diphtheria toxin A transgene are seen on day 12, when apoptotic cells appear in the area of elongation. In hemizygous embryos, ocular development is relatively normal until day 17 when the lens and eye are slightly smaller than normal and the lens vesicle is filled with abnormal lens material. At this time, the posterior capsule of the lens may rupture, releasing abnormal lens material which disperses throughout the eye, perturbing growth and other ocular structures. Additional breaks may subsequently occur and the ultimate morphology of the hemizygotes correlates with when the posterior capsule ruptures, how much lens material is released, and where it disperses. In homozygous embryos, due to extensive ablation of lens fiber cells, the "lens" becomes a diminutive mass of abnormal lens material, posteriorly located within the eye, and otherwise unable to fulfill its mechanical or inductive role in the development of the cornea, anterior chamber, iris, ciliary epithelium, and zonules with the result that all of these structures are markedly abnormal or absent. In addition, the lens is necessary for the accumulation of vitreous which in turn is required for the growth of the eye as a whole. In homozygous animals, vitreous does not accumulate and severe microphthalmia results. CONCLUSIONS: This study confirms and extends previous observations and conclusions on the central, orchestrating role of the lens in the development of the eye and illustrates the power of transgenic technology to elucidate the finer points of mammalian ocular development.     

虹膜膨隆变形及房角开放度的实验研究

目的对原有实验系统进行改进,并对兔眼虹膜在不同前后房压强差产生的膨隆变形及房角开放度进行实验研究。方法在保持虹膜环状形态结构和组织活性特征的前提下,搭建模拟完全瞳孔阻滞和虹膜膨隆的实验平台,获得兔眼虹膜随前后房压强差变化时的膨隆变形二维图像;再利用立体视觉技术得到膨隆变形的三维信息,并计算出膨隆曲线上虹膜根部所在点的切线斜率和虹膜膨隆最高点的曲率半径,由此对房角开放度进行衡量。结果当前后房压强差在50～200Pa之间时,虹膜根部斜率在0.29～0.55范围内逐渐增大,曲率半径在16.13～6.67的范围内迅速减小,房角在30°～15°的范围内变化;而当前后房压强差增大到200～600Pa之间时,虹膜根部斜率在0.55～0.76的范围内逐渐增大,曲率半径在6.67～4.25的范围内逐渐减小,房角在15°～10°的范围内缓慢减小。结论本文提出了一种可行的定量研究虹膜膨隆变形及房角开放度的理论和实验方法,研究结果与临床观察及研究相一致。     

Ocular changes in hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome (HFRS) is a rodent-originating zoonotic disease caused by Puumala and Dobrava viruses, which belong to the genus Hantavirus. The most prominent ocular change in HFRS is transient myopia, which lasts for up to one week and is due to a forward movement of the ocular anterior diaphragm and thickening of the lens. Other ophthalmic manifestations of HFRS are eyelid edema, conjunctival injection with or without hemorrhages, chemosis, anterior uveitis, retinal edema with or without hemorrhages, and photophobia. Acute glaucoma attacks, which are rare, could be explained by the increased intraocular pressure (IOP) due to edema and hemorrhage in the ciliary body, causing anterolateral rotation, relaxation of the zonules, and anterior movement of the lens. They are treated with mydriatic-cycloplegic and corticosteroid eye drops and with furosemide. However, there are also controversial reports on decreased IOP during the acute phase of HFRS. Despite the fact that ocular symptoms in HFRS are common generally they do not require any medical therapy and the recovery of the patients is complete.     

The morphology of the iridocorneal angle in the eye of buffaloes (Bos bubalis): a light and scanning electron microscopic study.

The morphology of the iridocorneal angle in the eye of the buffalo (Bos bubalis) was studied in eighteen eyes using light and scanning electron microscope (SEM). The buffalo iridocorneal angle included the pectinate ligament, the ciliary cleft, the trabecular meshwork (uveal and corneoscleral) and the angular aqueous plexus. The pectinate ligament was prominent anteriorly and appeared as strong, thick compact structure. The strands of the pectinate ligament were short and had narrow spaces between them as observed by SEM. The ciliary cleft appeared quadrilateral and contained large amount of trabecular tissue that could be divided into two parts, the uveal part and the corneoscleral part. The uveal meshwork was the internal part of the trabecular meshwork. It occupied wide area in the anterior region and narrow area in the posterior one. It composed of thick-pigmented trabeculae in the anterior part, which became thin and loose in the posterior part. Their intertrabecular spaces were large and wide anteriorly. The corneoscleral meshwork was the external part of the trabecular meshwork. It was narrow anteriorly and widened posteriorly. Their trabeculae were non-pigmented and closely arranged and the intertrabecular spaces were small. The angular aqueous plexus consisted of four to five veins. They were located between the outer border of the corneoscleral meshwork and the inner border of the sclera. These results of the iridocorneal angle suggest important implications for understanding the glaucoma disease in buffaloes.     

Intracapsular Organization of Ciliary Zonules in Monkey Eyes

Ciliary zonules are responsible for changing the curvature of a lens in the dioptric focus of an eye. Present established theory is based on the relaxation of zonular superficial fasciculi affixed to the capsular surface, thereby inducing the change of anterior‐ and posterior lens curvature causing spontaneous liquid movement of lens material. To achieve precise focusing at any distance, a more active functional organization should exist. The present studies were performed to determine not only the surface attachment but also the intracapsular affix of zonules on monkey eyes. In addition, the development of focusing in newborn and presbyopia is analyzed. Histology was prepared by conventional and molecular immunofluorescence stainings on the compositions of zonules with fibrillin‐1 (FBN 1) and lens capsule with collagen IV (COL IV), and in situ hybridization (ISH) analyses on frozen sections. Superficial circumferential attachments of zonule were found radially oriented between ciliary processes and anterior/posterior lens capsules forming a triangular figure. Two functional intralayer integrations were found above them; anterior‐posterior crossed fibers over the equator and radial fibers distributed toward the anterior or posterior polar areas. These fibers were bound tightly to the deep layer connective tissues close to the lens epithelium. Fine zonular fibers were aggregated, gradually forming bundles and bifurcated again on the way to the capsule. The lateral striped staining pattern in bundles suggested their elastic nature. Response of α‐helixes of collagen IV immunostaining was more positive on α‐1,2,4 than α‐3,5,6 on anterior‐ and posterior lens capsules. Newborn eyes revealed not fascicular but fine membranous zonules on the lens surface and small ciliary processes. ISH analysis revealed high synthetic expression of FBN 1 mRNA in cytoplasm of nonpigmented epithelial cells of ciliary processes. The synthetic expression of FBN 1 declined with aging. According to the mechanism of accommodation, active dynamic movement of anterior or posterior capsules play the main role of changing the lens configuration by two intralayer zonular integrations, including anterior‐posterior crossed fibers over the equator and radial fibers toward anterior or posterior polar areas acting with coordinated contraction of circular or longitudinal ciliary muscles. The developmental change on focusing is brought about by synthesis of FBN 1 in the newborn eye. Anat Rec 293:1797–1804, 2010. © 2010 Wiley‐Liss, Inc.     

Iris melanoma

The iris is the least common site of primary uveal melanoma. The prognosis of iris melanoma is better than that of melanoma of the ciliary body and choroid, but the reason for this difference is unclear. One possible explanation is that iris melanoma is smaller than its posterior segment counterparts at the time of diagnosis. Most iris melanomas are spindle cell types, according to a modified Callender classification system. There is evidence that the proliferation of melanocytes of the anterior iris surface (iris plaque) and diffuse stromal invasion may be risk factors for local recurrence and metastasis, respectively.     

Connections between Adrenergic Nerves and other Tissue Components in the Eye

The connections between adrenergic nerve fibres and other ocular structures were studied in normal embryonic material (man, dogs, cats, guinea-pigs, and rats) as well as with a special vessel injection technique (adult rats, guinea-pigs, and rabbits). It was established that adrenergic fibres are a normal constituent of the cornea. The adrenergic nerves were more numerous in the embryo than in the adult, and also occurred within the embryonic corneal epithelium. These intraepithelial fibres disappear shortly after birth. Adrenergic fibres running in the connective tissue without connection to vessels were further found in the iris, the limbus region, the chamber angle (of the guinea-pig predominantly) and in the chorioid. It cannot be excluded that these fibres innervate some connective tissue component. In the sphincter pupillae, only a few adrenergic fibres were connected to the vessels, such as was the case also in the ciliary muscle of the guinea-pig. Under the ciliary epithelium of the ciliary body and the ciliary processes there was a thick and dense plexus of adrenergic fibres. Only a restricted number of them was associated with the vessels. The “capillaries” of the ciliary processes were remarkable in that they seemed to possess adrenergic fibres. No adrenergic innervation to the melanophores was apparent.